Have you ever printed an image that looked red and green on screen but when it was printed, it ended up with purple and green? Even though the differences were not quite so dramatic, the way images look on screen differs from the way they look when printed. Calibrating the printer insures that what you print is consistent with what you see on-screen.
Printers could produce excellent color output, but tend to drift over time, causing consistency problems for users. Most software bundled with the printers now come with some type of calibration program. The purpose of these calibration utilities is to allow users to correct the changes in print quality caused due to changes in temperature, humidity, toner/ink, paper and use over time.
